U.S. patent number 6,516,589 [Application Number 09/591,412] was granted by the patent office on 2003-02-11 for method and machine for wrapping a product in a sheet of heat-seal wrapping material.
This patent grant is currently assigned to G. D Societa' per Azioni. Invention is credited to Fiorenzo Draghetti, Luca Federici.
United States Patent |
6,516,589 |
Draghetti , et al. |
February 11, 2003 |
**Please see images for:
( Certificate of Correction ) ** |
Method and machine for wrapping a product in a sheet of heat-seal
wrapping material
Abstract
A method and machine for wrapping a product in a sheet of
heat-seal wrapping material, whereby the product is wrapped in the
sheet of wrapping material to form a product having an outer
wrapping in turn having three distinct overlap portions, i.e.
portions having at least two superimposed layers of the sheet of
wrapping material; and the outer wrapping is stabilized, as the
product is conveyed continuously inside a respective same pocket,
by a seal formed at each of the three overlap portions.
Inventors: |
Draghetti; Fiorenzo (Medicina,
IT), Federici; Luca (Bologna, IT) |
Assignee: |
G. D Societa' per Azioni
(Bologna, IT)
|
Family
ID: |
11344045 |
Appl.
No.: |
09/591,412 |
Filed: |
June 12, 2000 |
Foreign Application Priority Data
|
|
|
|
|
Jun 10, 1999 [IT] |
|
|
BO99A0316 |
|
Current U.S.
Class: |
53/466; 53/376.7;
53/377.8 |
Current CPC
Class: |
B29C
66/8226 (20130101); B65B 11/42 (20130101); B65B
51/14 (20130101); B29C 66/4312 (20130101); B29C
66/431 (20130101); B29C 66/4322 (20130101); B29C
66/843 (20130101); B29C 66/1122 (20130101); B29C
65/02 (20130101); B29C 66/843 (20130101); B29C
65/00 (20130101) |
Current International
Class: |
B29C
65/00 (20060101); B65B 11/06 (20060101); B65B
11/42 (20060101); B65B 51/14 (20060101); B65B
011/00 () |
Field of
Search: |
;53/148,234,466,376.7,377.8,387.3,479,491 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
3046709 |
|
Oct 1981 |
|
DE |
|
0795474 |
|
Sep 1997 |
|
EP |
|
Primary Examiner: Smith; Scott A.
Assistant Examiner: Nathaniel; Chukwurah
Attorney, Agent or Firm: Ladas & Parry
Claims
What is claimed is:
1. A method of wrapping a product in a sheet of heat-seal wrapping
material, the method comprising the steps of wrapping the product
(2) in said sheet of wrapping material (3) to form a tubular
wrapping (13) comprising a longitudinal first overlap portion
(13a), defined by superimposed portions of said sheet of wrapping
material (13), and two projecting tubular end portions (14);
folding each of said tubular end portions (14) onto the product (2)
to form an outer wrapping (36) having said longitudinal first
overlap portion and two further end overlap portions (36a); and
feeding said product (2) along a sealing path (P1), along which,
said three overlap portions (13a, 36a) are stabilized by three
sealing operations; wherein said product (2) is fed along said
sealing path (P1) by a respective pocket (37), which is fed
continuously along the sealing path (P1) and on which said three
overlap portions are sealed by said three sealing operations.
2. A method as claimed in claim 1, wherein said first overlap
portion (13a) is pre-stabilized by a further spot sealing operation
prior to the sealing operation on said sealing path.
3. A method as claimed in claim 1, wherein said three sealing
operations are performed simultaneously by respective longitudinal
(70) and end (60) sealing means.
4. A method as claimed in claim 3, wherein said end and
longitudinal sealing means (60, 70) are maintained contacting the
respective said overlap portions (36a, 13a) substantially
throughout the travel of said product (2) along said sealing path
(P1).
5. A method as claimed in claim 3, wherein each said tubular end
portion (14) is folded by respective wrapping means (34); said end
sealing means (60) being brought into engagement with the
respective said further end overlap portions (36a) when said
wrapping means (34) are still positioned engaging the respective
tubular end portions (14).
6. A method as claimed in claim 1, wherein said product (2) is fed
along said sealing path (P1) with a longitudinal axis (2a) of the
product oriented crosswise to a traveling direction (41) of the
product (2), and with said first overlap portion (13a) located
frontwards in said traveling direction (41), and the two said
further end overlap portions (36a) located on opposite sides of the
sealing path (P1).
7. A method as claimed in claim 6, wherein said product (2) is fed
along said sealing path (P1) gripped by a gripping device (46)
movable along the sealing path (P1) with said product and which
comprises two lateral jaws (47) located on opposite sides of the
sealing path (P1) and each engaging a respective said further end
overlap portion (36a), each said lateral jaw (47) comprising
respective end sealing means (60) for stabilizing the respective
said further end overlap portion (36a); and a transverse jaw (48)
located in front of said two lateral jaws (47) in said traveling
direction (41), said transverse jaw (48) engaging said first
overlap portion (13a) and comprising longitudinal sealing means
(70) for stabilizing said first overlap portion (13a).
8. A machine for wrapping a product in a sheet of heat-seal
wrapping material, the machine comprising first wrapping means (5)
for wrapping the product (2) in said sheet of wrapping material (3)
and forming a tubular wrapping (13) comprising a longitudinal first
overlap portion (13a), defined by superimposed portions of the
sheet of wrapping material (3), and two projecting tubular end
portions (14); second wrapping means (34) for folding each said
tubular end portion (14) to form an outer wrapping (36) having two
further end overlap portions (36a); sealing means (60, 70) located
along a sealing path (P1), and each for performing a respective
sealing operation on a respective said overlap portion (36a, 13a);
and conveying means (38) for feeding said product (2) along said
sealing path (P1); wherein said conveying means (38) comprises a
single conveying pocket (37) for said product (2); first actuating
means (40) for feeding said pocket (37) continuously along said
sealing path (P1), said sealing means being positioned at said
sealing path to seal said first overlap portion and said two end
overlap portions as said product advances on said sealing path.
9. A machine as claimed in claim 8, comprising further sealing
means (16) for pre-stabilizing said first overlap portion (13a) by
means of a spot seal.
10. A machine as claimed in claim 8, wherein said sealing means
(60, 70) comprise two end sealing devices (60) located parallel to
and on opposite sides of said sealing path (P1), and a longitudinal
sealing device (70) located crosswise to said sealing path (P1);
second actuating means (40, 50) being provided to move said two end
sealing devices (60) and said longitudinal sealing device (70)
simultaneously into a griping position in which said two end
sealing devices and said longitudinal sealing devices (60, 70) are
positioned contacting the respective said overlap portions (36a,
13a).
11. A machine as claimed in claim 10, wherein said second actuating
means (49, 50) comprises cam means (50) for maintaining said two
end sealing devices and said longitudinal sealing device (60, 70)
in said gripping position substantially throughout the travel of
the product (2) along said sealing path (P1).
12. A machine as claimed in claim 10, wherein said second wrapping
means (34) and said two end sealing devices (60) are so arranged as
to all engage said outer wrapping (36) at an input of said sealing
path (P1).
13. A machine as claimed in claim 8, wherein said product (2) is
positioned, along said sealing path (P1), with a longitudinal axis
(2a) of the product oriented crosswise to a traveling direction
(41) of the product (2), and with said first overlap portion (13a)
located frontwards in said traveling direction (41), and the two
said further end overlap portions (36a) located on opposite sides
of the sealing path (P1); the machine further comprising a gripping
device (46) movable along the sealing path (P1) and which comprises
two lateral jaws (47) located on opposite sides of the sealing path
(P1) and each engaging a respective said further end overlap
portion (36a), each said lateral jaw (47) comprising respective end
sealing means (60) for stabilizing the respective said further end
overlap portion (36a); and a transverse jaw (48) located in front
of said two lateral jaws (47) in said traveling direction (41),
said transverse jaw (48) engaging said first overlap portion (13a)
and comprising longitudinal sealing means (70) for stabilizing said
first overlap portion (13a).
Description
The present invention relates to a method of wrapping a product in
a sheet of heat-seal wrapping material.
The present invention is particularly advantageous for use on
machines for cellophaning packets of cigarettes, to which the
following description refers purely by way of example.
BACKGROUND OF THE INVENTION
Known machines for cellophaning packets of cigarettes normally
comprise a step-operated first wrapping wheel on which a sheet of
heat-seal wrapping material is wound about a packet of cigarettes
to form a tubular wrapping, which is stabilized by means of a
longitudinal seal, and which comprises two tubular end portions,
each projecting from a respective end wall of the packet. The
longitudinal seal is made by a sealing device mounted at a fixed
sealing station, and which, at each stop of the first wrapping
wheel, is brought into contact with a longitudinal overlap portion
of two opposite portions of the sheet of wrapping material.
At the output of the first wrapping wheel, the packet and
respective tubular wrapping are normally fed through a folding
station where the projecting tubular portions of the tubular
wrapping are folded onto respective end walls to form two further
overlap portions closing the ends of an outer overwrapping. The two
overlap portions are then stabilized by two end seals as the packet
is conveyed on a continuously operated second wrapping wheel.
Finally, the overwrapped packet is normally fed to an output
station where it is normally heat treated to shrink the outer
wrapping about the packet.
Known cellophaning machines of the type described above have
several drawbacks, mainly due to the fact that, over and above a
given operating speed, the stops of the first wrapping wheel are
not long enough to enable correct execution of the longitudinal
seal.
Moreover, a further drawback of known cellophaning machines of the
type described above lies in the longitudinal seal being made
separately from the end seals, which means the tubular wrapping, at
the output of the first wrapping wheel, may undergo localized heat
shrinking at the longitudinal overlap portion only, thus impairing
correct formation of the outer wrapping by shortening and
tightening the overlap portion with respect to the rest of the
tubular wrapping.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method of
wrapping a product in a sheet of heat-seal wrapping material,
designed to eliminate the aforementioned drawbacks.
According to the present invention, there is provided a method of
wrapping a product in a sheet of heat-seal wrapping material, the
method comprising the steps of wrapping the product in said sheet
of wrapping material to form a tubular wrapping comprising a
longitudinal first overlap portion, defined by superimposed
portions of said sheet of wrapping material, and two projecting
tubular end portions; folding each of said tubular end portions
onto the product to form an outer wrapping having two further end
overlap portions; and feeding said product along a sealing path,
along which, said three overlap portions are stabilized by three
sealing operations; and being characterized in that said product is
fed along said sealing path by a respective same pocket, which is
fed continuously along the sealing path.
The present invention also relates to a machine for wrapping a
product in a sheet of heat-seal wrapping material.
According to the present invention, there is provided a machine for
wrapping a product in a sheet of heat-seal wrapping material, the
machine comprising first wrapping means for wrapping the product in
said sheet of wrapping material and forming a tubular wrapping
comprising a longitudinal first overlap portion, defined by
superimposed portions of the sheet of wrapping material, and two
projecting tubular end portions; second wrapping means for folding
each said tubular end portion to form an outer wrapping having two
further end overlap portions; sealing means located along a sealing
path, and each for performing a respective sealing operation on a
respective said overlap portion; and conveying means for feeding
said product along said sealing path; and being characterized in
that said conveying means comprise a single conveying pocket for
said product; first actuating means being provided to feed said
pocket continuously along said sealing path.
BRIEF DESCRIPTION OF THE DRAWINGS
A non-limiting embodiment of the present invention will be
described by way of example with reference to the accompanying
drawings, in which:
FIG. 1 shows a schematic side view, with parts enlarged and parts
removed for clarity, of a preferred embodiment of the machine
according to the present invention;
FIG. 2 shows an enlarged view in perspective of a detail in FIG.
1;
FIG. 3 shows an axial section of the FIG. 2 detail.
DETAILED DESCRIPTION OF THE INVENTION
Number 1 in FIG. 1 indicates as a whole a cellophaning machine for
wrapping packets 2 of cigarettes in respective sheets 3 of
transparent heat-seal wrapping material.
Machine 1 comprises a wrapping wheel 5 fitted to a powered shaft 6,
which is mounted to rotate in steps and in a given direction
(clockwise in FIG. 1) about an axis 7 perpendicular to the FIG. 1
plane.
Wheel 5, of known type, comprises a number of pockets 8, which are
equally spaced along the periphery of wheel 5, are substantially
U-shaped, and are open both radially and axially outwards.
When stopped at a loading station 9, each pocket 8 receives a
respective sheet 3 of wrapping material fed to station 9 by a known
supply device 10, and a respective packet 2, which is inserted
inside respective pocket 8 to fold sheet 3 into a U about packet
2.
In connection with the above, it should be pointed out that, on
machine 1, packet 2 is fed by wheel 5, and by successive conveying
devices described later on, along a wrapping path P with the
longitudinal axis 2a of the packet oriented crosswise at all times
to path P and to the FIG. 1 plane.
As packet 2 and respective sheet 3 are fed by wheel 5 between
loading station 9 and an unloading station 11, sheet 3 is wrapped
about packet 2 (as of said U-shaped configuration) by two known
folding devices 12a and 12b to form a tubular wrapping 13, which
comprises a longitudinal overlap portion 13a, defined by two
superimposed portions of sheet 3, and two tubular end portions 14,
each of which projects from a respective end wall 15 of packet
2.
When wheel 5 is stopped, longitudinal overlap portion 13a is
pre-stabilized by means of a spot seal made by a sealing device 16,
which is substantially fork-shaped, is mounted at a fixed sealing
station, and is activated in known manner to move back and forth
linearly to and from wheel 5 in a substantially radial direction to
effect said spot seal.
Wheel 5 comprises, in known manner, two coaxial, parallel disks 17
(only one shown in FIG. 1) fitted to shaft 6 and each comprising a
number of peripheral seats 18, each of which defines a respective
pocket 8 together with a corresponding seat 18 on the other disk
17.
Machine 1 also comprises an endless conveyor 19 in turn comprising
a belt 20 looped about two pulleys 21--one of which is powered
continuously--having respective axes 22 parallel to axis 7 of wheel
5. Belt 20 comprises a number of push members 23 equally spaced
along belt 20 and defining a succession of pockets 24, the length
of each of which is at least equal to the width of a packet 2
measured parallel to path P.
At said unloading station 11, conveyor 19 extends between disks 17
of wheel 5 to enable one of push members 23 to extract a respective
packet 2 and respective tubular wrapping 13 from respective pocket
8, and feed packet 2 and tubular wrapping 13 through an input
portion of a folding station 25, which is defined partly by
conveyor 19 and partly by a channel 26 located in series with
conveyor 19 and defined at the bottom by a horizontal plate 27, and
at the top by a bottom conveying branch of an endless conveyor
28.
Conveyor 28 comprises a belt 29 looped about two pulleys 30--one of
which is powered continuously having respective axes 31 parallel to
axes 22. Belt 29 comprises a number of push members 32 equally
spaced along belt 29 and defining a succession of pockets 33, each
of which is fed forwards in time with a pocket 24 of conveyor 19 to
receive packet 2 and tubular wrapping 13 housed inside pocket 24,
and feed packet 2 and tubular wrapping 13 through an output portion
of folding station 25.
For each of the two tubular portions 14, station 25 comprises a
series of known folding devices 34 for folding the relative tubular
portion 14 in known manner onto the respective end wall 15 of
respective packet 2, so that, along station 25, an overwrapped
packet 35 is formed comprising a closed outer wrapping 36 having
two end overlap portions 36a, each defined by a number of
superimposed portions of sheet 3 of wrapping material.
At the output of station 25, overwrapped packet 35 is transferred,
as described later on, from respective pocket 33 to a pocket 37 of
a sealing wheel 38. Sealing wheel 38 comprises, in known manner,
two coaxial, parallel drums 39 fitted, a given distance apart, to a
powered shaft 40 rotated continuously and in a given direction 41
(clockwise in FIG. 1) about an axis 42 parallel to axis 7 of wheel
5.
Pockets 37 are equally spaced along the periphery of wheel 38, are
fed forwards in time with pockets 33, and each comprise, for each
of the two drums 39, a respective substantially flat supporting
surface 44 formed on the outer surface of relative drum 39, and a
respective push member 45, which projects radially from the outer
surface of relative drum 39 to engage the rear of respective
overwrapped packet 35. Each pocket 37 also comprises a respective
gripping and sealing device 46 for retaining respective overwrapped
packet 35 inside pocket 37 and in contact with both respective push
member 45 and respective supporting surface 44.
In connection with the above, it should be pointed out that
overwrapped packet 35 is fed into respective pocket 37 "flat", i.e.
with two major lateral surfaces of the packet positioned
horizontally, with axis 2a oriented crosswise to path P, and with
longitudinal overlap portion 13a located frontwards in direction
41.
With reference to FIG. 2, each gripping and sealing device 46
comprises two lateral jaws 47 located on opposite sides of path P;
and a transverse jaw 48 located crosswise to path P and to the
front of lateral jaws 47 in direction 41. Jaws 47 and 48 are
supported by a shaft 49, which is mounted for rotation through the
two drums 39, and is oscillated--with respect to drums 39 and by a
known cam device 50 housed inside one of drums 39--about an axis 51
parallel to axis 42.
With reference to FIG. 3, the two lateral jaws 47 are positioned
facing each other, and each comprise a respective tubular body 52
fitted to shaft 49 and having a cylindrical outer surface 53, the
axis 54 of which forms a given angle 55 with axis 51. Each jaw 47
also comprises a ball bearing 56 having an inner ring fitted to
surface 53 of tubular body 52; and a bar 57 in turn comprising a
central hub 58 fitted to an outer ring of bearing 56, and two
opposite arms 59 extending radially outwards from hub 58. The two
arms 59 are fitted respectively, on the free ends, with a known
sealing device 60, and a tappet roller 61 fitted in rotary manner
to respective arm 59 and engaging a track 62, which is formed on
relative drum 39 and is parallel to axis 51 of shaft 49 and
crosswise to path P.
When shaft 49 oscillates about axis 51, bar 57 would therefore also
oscillate about axis 51 if it were not forced, by track 62 and by
angle 55 formed between axes 51 and 54, to oscillate about an axis
63 extending perpendicular to the FIG. 3 plane at the intersection
of axes 51 and 54.
Transverse jaw 48 comprises a crank 64 fitted to shaft 49, between
tubular bodies 52 of the two lateral jaws 47, and connected to a
rocker arm 65 fitted to a shaft 66, the opposite ends of which are
mounted for rotation through the two drums 39 to enable shaft 66 to
rotate, with respect to the two drums 39 and by virtue of said cam
device 50, about an axis 67 parallel to axis 51. Rocker arm 65
comprises a first arm 68 connected in rotary manner, via the
interposition of a connecting rod 68a, to the free end of crank 64;
and a second arm 69 supporting a known sealing device 70 extending
crosswise to direction 41 and to path P.
In actual use, overwrapped packet 35 is fed to the output of
folding station 25 inside respective pocket 33 and in time with a
respective pocket 37. At the output of station 25, when shaft 49 is
oscillated about axis 51 and portions of folding devices 34 are
still positioned engaging outer wrapping 36, the two lateral jaws
47 and transverse jaw 48 are all moved simultaneously from a
detached position to a gripping position (FIG. 2) in which sealing
devices 60 and sealing device 70 are respectively positioned
contacting overlap portions 36a and overlap portion 13a, so as to
clamp overwrapped packet 35 inside respective pocket 37 and
stabilize outer wrapping 36 by means of two end seals at overlap
portions 36a and a longitudinal edge seal at overlap portion
13a.
Jaws 47 and 48 are maintained in the gripping position along the
whole of sealing path P1, which forms part of wrapping path P and
extends along a curved plate 71 extending, from the output of
folding station 25, along an arc of about 180.degree. about the
periphery of sealing wheel 38.
At the output of wheel 38, jaws 47 and 48 are moved into the
detached position to unload overwrapped packet 35 onto the top
conveying branch of an output conveyor 72 forming part of a
heat-shrink device 73 for heat treating overwrapped packet 35 to
shrink sheet 3 of wrapping material about packet 2.
* * * * *